Changes in collagen synthesis by human bone marrow fibroblasts with progressive subcultivation

Bone marrow fibroblasts from normal and leukemic patients were used to investigate the relationship between serial subcultivation and changes in collagen synthesis. A regime was established to generate subcultures up to 35 cumulative population doublings (CPDs) in normal cells and to 9 CPDs in leukemic cells. In both types of cells, collagen synthesis decreased as subcultivation progressed. In normal cells, collagen synthesis was reduced to 10% of the original levels at 18 CPDs and in leukemic cells at 8 CPDs. In normal fibroblasts, collagen synthesis was more profoundly affected than overall protein synthesis by subcultivation. In acute lymphoblastic leukemia-derived fibroblasts, the decrease in collagen synthesis paralleled that of total protein.